RES 131

1
RES 131

• Pulmonary Functions

2
Good Start of Test

• Start of test must be quick and forceful
• No excessive hesitation
• Best evaluated using the Flow-Volume tracing
• No excessive back extrapolated volume

3
Good Start of Test
4
No Coughing

• Especially during the first 1 second of the
  maneuver
• Best if no coughing present during maneuver,
  however
• Some patients cough near the end of each test, if
  present then document

5
No Coughing
6
No Variable Flow

• Flow rate should be maximal and consistent
  throughout testing
• Volume-Time and Flow-Volume tracings should be
  smooth

7
No Variable Flow
8
No Early Termination of Effort

• Best if maneuver lasts at least six (6) seconds
• Less than six seconds acceptable if a plateau of
  al least one (1) second is present
• If patient is unable to meet the above criteria,
  document in comment section

9
No Early Termination of Effort
10
Reproducibility

• Spirometry induced bronchospasm
• Each effort gets worse
• Patient eventually reaches a plateau, however
  they may be too short of breath to continue.
• Which effort to report?
• Best effort unless pre and post bronchodilator
  study, then report the worst effort.

11
Spirometry Induced Bronchospasm
12
Temperature Correction

• Charles law states that the volume occupied by a
  given quantity of gas is directly related to
  temperature
• Body temperature gas is exhaled into a room
  temperature spirometer, therefore the volume
  decreases
• Temperature correction allows us to know the
  volume of gas as it was in the body

13
Temperature Correction

• Charles law states that the volume occupied by a
  given quantity of gas is directly related to
  temperature
• Body temperature gas is exhaled into a room
  temperature spirometer, therefore the volume
  decreases
• Temperature correction allows us to know the
  volume of gas as it was in the body

14
Temperature Correction

• The volume measured by the spirometer is
  reflected at ATPS (atmospheric temperature,
  pressure, saturated)
• It must be corrected to BTPS (body temperature,
  pressure, saturated)

15
Temperature Correction

• Formula for calculation of temperature correction
  factor

16
Temperature Correction

• Conversion factor is multiplied by the ATPS
  volume to find the BTPS volume.

17
Back Extrapolation

• Extrapolated Volume may not exceed 5 of the FVC